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13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/bitops.h>
16#include <linux/errno.h>
17#include <linux/fs.h>
18#include <linux/io.h>
19#include <linux/kernel.h>
20#include <linux/miscdevice.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
23#include <linux/types.h>
24#include <linux/uaccess.h>
25#include <linux/watchdog.h>
26#include <linux/timer.h>
27#include <linux/jiffies.h>
28#include <linux/interrupt.h>
29#include <linux/ptrace.h>
30#include <linux/resource.h>
31#include <linux/platform_device.h>
32
33#include <bcm63xx_cpu.h>
34#include <bcm63xx_io.h>
35#include <bcm63xx_regs.h>
36#include <bcm63xx_timer.h>
37
38#define PFX KBUILD_MODNAME
39
40#define WDT_HZ 50000000
41#define WDT_DEFAULT_TIME 30
42#define WDT_MAX_TIME 256
43
44static struct {
45 void __iomem *regs;
46 struct timer_list timer;
47 unsigned long inuse;
48 atomic_t ticks;
49} bcm63xx_wdt_device;
50
51static int expect_close;
52
53static int wdt_time = WDT_DEFAULT_TIME;
54static bool nowayout = WATCHDOG_NOWAYOUT;
55module_param(nowayout, bool, 0);
56MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
57 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
58
59
60static void bcm63xx_wdt_hw_start(void)
61{
62 bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
63 bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
64 bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
65}
66
67static void bcm63xx_wdt_hw_stop(void)
68{
69 bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
70 bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
71}
72
73static void bcm63xx_wdt_isr(void *data)
74{
75 struct pt_regs *regs = get_irq_regs();
76
77 die(PFX " fire", regs);
78}
79
80static void bcm63xx_timer_tick(unsigned long unused)
81{
82 if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
83 bcm63xx_wdt_hw_start();
84 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
85 } else
86 pr_crit("watchdog will restart system\n");
87}
88
89static void bcm63xx_wdt_pet(void)
90{
91 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
92}
93
94static void bcm63xx_wdt_start(void)
95{
96 bcm63xx_wdt_pet();
97 bcm63xx_timer_tick(0);
98}
99
100static void bcm63xx_wdt_pause(void)
101{
102 del_timer_sync(&bcm63xx_wdt_device.timer);
103 bcm63xx_wdt_hw_stop();
104}
105
106static int bcm63xx_wdt_settimeout(int new_time)
107{
108 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
109 return -EINVAL;
110
111 wdt_time = new_time;
112
113 return 0;
114}
115
116static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
117{
118 if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
119 return -EBUSY;
120
121 bcm63xx_wdt_start();
122 return nonseekable_open(inode, file);
123}
124
125static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
126{
127 if (expect_close == 42)
128 bcm63xx_wdt_pause();
129 else {
130 pr_crit("Unexpected close, not stopping watchdog!\n");
131 bcm63xx_wdt_start();
132 }
133 clear_bit(0, &bcm63xx_wdt_device.inuse);
134 expect_close = 0;
135 return 0;
136}
137
138static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
139 size_t len, loff_t *ppos)
140{
141 if (len) {
142 if (!nowayout) {
143 size_t i;
144
145
146 expect_close = 0;
147
148 for (i = 0; i != len; i++) {
149 char c;
150 if (get_user(c, data + i))
151 return -EFAULT;
152 if (c == 'V')
153 expect_close = 42;
154 }
155 }
156 bcm63xx_wdt_pet();
157 }
158 return len;
159}
160
161static struct watchdog_info bcm63xx_wdt_info = {
162 .identity = PFX,
163 .options = WDIOF_SETTIMEOUT |
164 WDIOF_KEEPALIVEPING |
165 WDIOF_MAGICCLOSE,
166};
167
168
169static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
170 unsigned long arg)
171{
172 void __user *argp = (void __user *)arg;
173 int __user *p = argp;
174 int new_value, retval = -EINVAL;
175
176 switch (cmd) {
177 case WDIOC_GETSUPPORT:
178 return copy_to_user(argp, &bcm63xx_wdt_info,
179 sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
180
181 case WDIOC_GETSTATUS:
182 case WDIOC_GETBOOTSTATUS:
183 return put_user(0, p);
184
185 case WDIOC_SETOPTIONS:
186 if (get_user(new_value, p))
187 return -EFAULT;
188
189 if (new_value & WDIOS_DISABLECARD) {
190 bcm63xx_wdt_pause();
191 retval = 0;
192 }
193 if (new_value & WDIOS_ENABLECARD) {
194 bcm63xx_wdt_start();
195 retval = 0;
196 }
197
198 return retval;
199
200 case WDIOC_KEEPALIVE:
201 bcm63xx_wdt_pet();
202 return 0;
203
204 case WDIOC_SETTIMEOUT:
205 if (get_user(new_value, p))
206 return -EFAULT;
207
208 if (bcm63xx_wdt_settimeout(new_value))
209 return -EINVAL;
210
211 bcm63xx_wdt_pet();
212
213 case WDIOC_GETTIMEOUT:
214 return put_user(wdt_time, p);
215
216 default:
217 return -ENOTTY;
218
219 }
220}
221
222static const struct file_operations bcm63xx_wdt_fops = {
223 .owner = THIS_MODULE,
224 .llseek = no_llseek,
225 .write = bcm63xx_wdt_write,
226 .unlocked_ioctl = bcm63xx_wdt_ioctl,
227 .open = bcm63xx_wdt_open,
228 .release = bcm63xx_wdt_release,
229};
230
231static struct miscdevice bcm63xx_wdt_miscdev = {
232 .minor = WATCHDOG_MINOR,
233 .name = "watchdog",
234 .fops = &bcm63xx_wdt_fops,
235};
236
237
238static int bcm63xx_wdt_probe(struct platform_device *pdev)
239{
240 int ret;
241 struct resource *r;
242
243 setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
244
245 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
246 if (!r) {
247 dev_err(&pdev->dev, "failed to get resources\n");
248 return -ENODEV;
249 }
250
251 bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
252 resource_size(r));
253 if (!bcm63xx_wdt_device.regs) {
254 dev_err(&pdev->dev, "failed to remap I/O resources\n");
255 return -ENXIO;
256 }
257
258 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
259 if (ret < 0) {
260 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
261 return ret;
262 }
263
264 if (bcm63xx_wdt_settimeout(wdt_time)) {
265 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
266 dev_info(&pdev->dev,
267 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
268 wdt_time);
269 }
270
271 ret = misc_register(&bcm63xx_wdt_miscdev);
272 if (ret < 0) {
273 dev_err(&pdev->dev, "failed to register watchdog device\n");
274 goto unregister_timer;
275 }
276
277 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
278 WDT_DEFAULT_TIME);
279
280 return 0;
281
282unregister_timer:
283 bcm63xx_timer_unregister(TIMER_WDT_ID);
284 return ret;
285}
286
287static int bcm63xx_wdt_remove(struct platform_device *pdev)
288{
289 if (!nowayout)
290 bcm63xx_wdt_pause();
291
292 misc_deregister(&bcm63xx_wdt_miscdev);
293 bcm63xx_timer_unregister(TIMER_WDT_ID);
294 return 0;
295}
296
297static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
298{
299 bcm63xx_wdt_pause();
300}
301
302static struct platform_driver bcm63xx_wdt_driver = {
303 .probe = bcm63xx_wdt_probe,
304 .remove = bcm63xx_wdt_remove,
305 .shutdown = bcm63xx_wdt_shutdown,
306 .driver = {
307 .name = "bcm63xx-wdt",
308 }
309};
310
311module_platform_driver(bcm63xx_wdt_driver);
312
313MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
314MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
315MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
316MODULE_LICENSE("GPL");
317MODULE_ALIAS("platform:bcm63xx-wdt");
318
